JP4125646B2

JP4125646B2 - Induction heating device

Info

Publication number: JP4125646B2
Application number: JP2003192369A
Authority: JP
Inventors: 清義高田; 直昭石丸; 保泉谷
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2003-07-04
Filing date: 2003-07-04
Publication date: 2008-07-30
Anticipated expiration: 2023-07-04
Also published as: EP1643807B1; CN100515146C; HK1081046A1; US20050242088A1; US7049564B2; EP1643807A4; KR101027405B1; EP1643807A1; JP2005026162A; ES2438187T3; KR20060025119A; WO2005004541A1; CN1698402A

Description

【０００１】
【発明の属する技術分野】
本発明は、赤外線センサを備えた誘導加熱装置に関する。
【０００２】
【従来の技術】
近年、火を使わない調理器等として、誘導加熱装置が市場に広まっている。図５及び図６を用いて、従来例の誘導加熱装置を説明する。
図５を用いて従来例１の誘導加熱装置を説明する。図５は、感熱素子を用いた従来例１の誘導加熱装置の構成を示す断面図である。従来例１の誘導加熱装置は、外郭を構成する本体１、非磁性体で形成されその上に調理容器５３を載置するトッププレート２、トッププレート２の下部に配置され調理容器５３を誘導加熱する誘導加熱コイル４、トッププレート２の裏面に圧接されその温度に応じた検出信号を出力する感熱素子５４、温度算出手段５１、制御手段５２を有する。従来例１の誘導加熱装置は、感熱素子を用いて、トッププレート２上に載置された調理容器５３の底面の温度を検出する。温度算出手段５１は、感熱素子５４の出力信号に基づいて調理容器５３の温度を算出する。制御手段５２は、温度算出手段５１から得た温度情報をもとに誘導加熱コイル４への電力の供給を制御する。
【０００３】
制御手段５２によって誘導加熱コイル４に高周波電流を供給する。誘導加熱コイル４が高周波磁界を発生する。この高周波磁界が調理容器５３と鎖交して、調理容器５３自身が誘導加熱され発熱する。調理容器５３内に収容している調理物は、調理容器５３の発熱によって加熱され、調理が進行する。制御手段５２は、温度算出手段５１が検知する温度信号に基づいて誘導加熱コイル４に供給する電力を調整して、調理物の温度を制御している。
【０００４】
感熱素子５４は調理容器５３の温度をトッププレート２を介して検知する。トッププレート２はセラミックによって構成されており、熱伝導率が小さい。そのため、感熱素子５４による調理容器５３の温度検知に遅れが生じ、従来の誘導加熱装置は熱応答性に劣るという課題が発生していた。
【０００５】
図６を用いて従来例２の誘導加熱装置を説明する。図６は、赤外線センサを用いた従来例２の誘導加熱装置の構成を示す断面図である。図６において、図５と異なるところは、感熱素子５４の代わりに赤外線センサ５を有することである。その他の構成要素は、図５と同一であるので同一符号を付し、説明を省略する。
赤外線センサ５は、トッププレート２の下部に配設され、調理容器５３の底面から放射される赤外線をトッププレート２越しに検知して温度に応じた信号を出力する。温度算出手段５１は、赤外線センサ５の出力信号に基づいて調理容器５３の温度を算出する。制御手段５２は、温度算出手段５１から得た情報をもとに誘導加熱コイル４への電力供給を制御する。
調理容器５３から放射される赤外線はトッププレート２を通過して赤外線センサ５に到達する。赤外線センサ５を用いた温度検出方式では、熱応答性に劣ると云う問題は克服されるものであった（例えば、特許文献１参照）。
【０００６】
【特許文献１】
特開平０３−１８４２９５号公報
【０００７】
【発明が解決しようとする課題】
しかしながら赤外線センサを用いた従来例２の誘導加熱装置の構成のように、赤外線センサ５が誘導加熱コイル４の近傍に配設されると、加熱調理中に発生する誘導加熱コイル４からの誘導磁界の影響を受けて、赤外線センサ５自体が発熱する。そのため従来の誘導加熱装置は、正確な温度検知ができず、安定した加熱制御ができなくなるという問題があった。
本発明は、上記従来の問題を解消することを課題とするもので、誘導加熱手段からの漏洩磁束の影響を受けることなく、赤外線センサが安定した温度検知を行う誘導加熱装置を提供することを目的とする。
【０００８】
【課題を解決するための手段】
上記課題を解決するため、本発明の誘導加熱装置は、外郭を構成する本体と、前記本体の上面に設けられ、被加熱調理容器を載置する少なくとも一つの載置部を有するトッププレートと、前記載置部の下方に設けられ、前記被加熱調理容器を加熱する誘導加熱手段と、前記誘導加熱手段の近傍に設けられ、前記被加熱調理容器から放射される赤外線を受光し、その光量に応じた検出信号を出力する赤外線センサと、前記赤外線センサが取り付けられ、前記検出信号に基づいて前記被加熱調理容器の温度を検知する制御基板と、前記赤外線センサの周囲を覆う筒体と、前記制御基板を覆う側部と、を有する一体で構成された防磁部材と、を有する。
本発明は、誘導加熱手段からの漏洩磁束の影響を受けることなく、赤外線センサが安定して高い精度で温度検知を行う誘導加熱装置を実現できるという作用を有する。
【０００９】
【発明の実施の形態】
請求項１に記載の発明は、外郭を構成する本体と、前記本体の上面に設けられ、被加熱調理容器を載置する少なくとも一つの載置部を有するトッププレートと、前記載置部の下方に設けられ、前記被加熱調理容器を加熱する誘導加熱手段と、前記誘導加熱手段の近傍に設けられ、前記被加熱調理容器から放射される赤外線を受光し、その光量に応じた検出信号を出力する赤外線センサと、前記赤外線センサが取り付けられ、前記検出信号に基づいて前記被加熱調理容器の温度を検知する制御基板と、前記赤外線センサの周囲を覆う筒体と、前記制御基板を覆う側部と、を有する一体で構成された防磁部材と、を有することを特徴とする誘導加熱装置である。
【００１０】
本発明によれば、赤外線センサは加熱調理中に発生する誘導加熱手段からの誘導磁界の影響を受けにくくなる。本発明は、誘導加熱コイルの磁気の影響により赤外線センサ自体が発熱することを抑える誘導加熱装置を実現できるという作用を有する。
本発明は、非磁性の筒体により赤外線センサ周辺の雰囲気温度の安定化を図ることができるため、正確に温度検知ができ、安定した加熱制御ができる誘導加熱装置を実現できるという作用を有する。
本発明は、赤外線センサが取り付けられ、その出力する検出信号に基づいて被加熱調理容器の温度を検知する制御基板を防磁部材の側部で覆うことにより、前記制御基板が誘導加熱コイルからの漏洩磁束の影響を受けることなく、赤外線センサによる安定した温度検知が行える誘導加熱装置を実現できるという作用を有する。
本発明は、防磁部材の筒体と側部とを一体で構成することにより、高い施工性を実現する。これにより、赤外線センサと防磁部材との取り付け位置精度を向上させることが出来る。本発明は、高い寸法精度を有し、部品点数が少なく、優れた組立作業性を有する誘導加熱装置を実現できるという作用を有する。
【００１１】
請求項２に記載の発明は、前記筒体は、略同軸にして二重の筒体に形成されることを特徴とする請求項１に記載の誘導加熱装置である。
本発明により、磁束が赤外線センサに洩れ込むことを防止する防磁効果をさらに高めるとともに、防磁部材の熱容量の増大により赤外線センサの周りの雰囲気の温度を更に安定して維持できる。本発明は、高い精度で温度検知を行う誘導加熱装置を実現できるという作用を有する。
【００１２】
請求項３に記載の発明は、内側の前記筒体と外側の前記筒体とのつなぎ部に開口部を有することを特徴とする請求項２に記載の誘導加熱装置である。
本発明は、外側の筒体が加熱された場合でも、開口部で熱切りすることにより、内側の筒体への熱伝導を少なくし、赤外線センサ周辺の雰囲気温度の大幅な上昇を防止する。本発明は、安定した温度検知が行える誘導加熱装置を実現できるという作用を有する。
【００１３】
請求項４に記載の発明は、前記防磁部材の材質はアルミであることを特徴とする請求項１に記載の誘導加熱装置である。アルミは、赤外線センサの反射率が高く（被加熱調理容器が放射した赤外線を少ない損失で赤外線センサに伝え）、アルミ自体の赤外線放射が少ない（被加熱調理容器が放射した赤外線のＳ／Ｎ比（信号対ノイズ比）を劣化させにくい。）。本発明は、高い精度で温度検知を行う誘導加熱装置を実現できるという作用を有する。
【００１４】
請求項５に記載の発明は、前記防磁部材はダイカスト製であって、前記筒体の内面は鏡面仕上げで形成されることを特徴とする請求項１に記載の誘導加熱装置である。本発明は、正確に赤外線を検知できる誘導加熱装置を実現できるという作用を有する。これにより、高い精度で複雑な形状の防磁部材を形成できる。十分な防磁効果を得るには防磁部材の厚さがある程度厚いことが好ましい。ダイカストにより最適の厚さで防磁部材を形成できる。ダイカストの筒体の内面を鏡面仕上げすることにより、被加熱調理容器が放射した赤外線を少ない損失で赤外線センサに伝えることが出来る。
筒体が二重である場合は内側の筒体の内面を鏡面仕上げすれば良い。
【００１６】
請求項６に記載の発明は、前記トッププレートの上面と前記赤外線センサの上面との間の距離は、１５ミリ〜３５ミリの範囲であることを特徴とする請求項１に記載の誘導加熱装置である。
赤外線センサのトッププレートからの距離が近いと、赤外線センサは誘導加熱手段からの漏洩磁束の影響を受けて熱くなり過ぎる。トッププレートからの距離が遠いと、被加熱調理容器から発せられる赤外線の入力が小さくなる。そのため、トッププレートの上面と赤外線センサの上面との間の距離は、１５ミリ〜３５ミリの範囲に設定する。この範囲において、赤外線センサは誘導加熱手段からの漏洩磁束の影響を受けにくく、且つ十分な量の赤外線を受光できる。好ましくは、トッププレートの上面と赤外線センサの上面との間の距離の最適値を２６ミリにする。
【００１７】
請求項７に記載の発明は、前記防磁部材の肉厚は、１．５ミリ〜５ミリの範囲であることを特徴とする請求項１に記載の誘導加熱装置である。防磁部材の肉厚が薄いと防磁効果が薄くなり、防磁部材の肉厚が厚いと、成形後、内部に巣が入り防磁効果が薄れる。そのため、防磁部材は、１．５ミリ〜５ミリの範囲でほぼ均等に成形する。好ましくは、防磁部材の標準肉厚を２ミリにする。
【００１８】
請求項８に記載の発明は、前記制御基板の下方を略覆うシールドプレートを更に有することを特徴とする請求項１に記載の誘導加熱装置である。
これにより、制御基板の下側から回り込む磁束を遮蔽し、その影響を防止できる。本発明は、更に漏洩磁束の影響を受けにくい誘導加熱装置を実現できるという作用を有する。
【００１９】
請求項９に記載の発明は、前記防磁部材、又は前記防磁部材及び前記シールドプレートは接地されることを特徴とする請求項１又は請求項８に記載の誘導加熱装置である。本発明は、更に漏洩磁束の影響を受けにくい誘導加熱装置を実現できるという作用を有する。
【００２０】
請求項１０に記載の発明は、前記防磁部材、又は前記防磁部材及び前記シールドプレートを保持する第１の樹脂カバーを更に有し、前記第１の樹脂カバーと、前記防磁部材又は前記防磁部材及び前記シールドプレートとは略閉空間を構成し、その中に前記赤外線センサと前記制御基板とを収納することを特徴とする請求項１又は請求項８に記載の誘導加熱装置である。
【００２１】
誘導加熱装置は、典型的には本体の下部にファンを有し、ファンは誘導加熱手段に冷却風を送ることで誘導加熱手段の発熱を抑えている。しかし、この風が赤外線センサの周りを通り抜けると、赤外線センサの周りの雰囲気温度が安定しなくなり、赤外線センサによる被加熱調理容器の温度検出精度が劣化する。本発明は、樹脂カバーと防磁部材とで略閉空間を構成して、その中に赤外線センサ及び制御基板を収納することにより、略閉空間に冷却風を通さない構造とする。本発明は、赤外線センサ及び制御基板の雰囲気温度を一定にして、高い精度で被加熱調理容器の温度を検出する誘導加熱装置を実現できるという作用を有する。
【００２２】
請求項１１に記載の発明は、前記赤外線センサと前記赤外線センサが取り付けられている回路基板との間に配置され、前記被加熱調理容器が放射する赤外線から前記回路基板を略遮蔽する第２の樹脂カバーを更に有することを特徴とする請求項１に記載の誘導加熱装置である。これにより、被加熱調理容器から放射された赤外線が経時的に回路基板を劣化させることを防止できる。
【００２３】
請求項１２に記載の発明は、前記第２の樹脂カバーは、前記赤外線センサを、前記回路基板から所定の高さの位置に保持することを特徴とする請求項１１に記載の誘導加熱装置である。第２の樹脂カバーが赤外線センサを回路基板から所定の高さの位置に安定に保持することにより、赤外線センサを磁性部材の筒体の底面より上に配置できる。これにより、被加熱調理容器が放射した赤外線を更に少ない損失で赤外線センサに伝えることが出来る。
【００２４】
請求項１３に記載の発明は、前記赤外線センサを載置する保持面を有する第２の樹脂カバーを更に有し、前記防磁部材が下方向に開口した凹部を有し、前記保持面が前記凹部の中に位置し、前記第２の樹脂カバー及び前記凹部で規定される空間の側面及び底面が略閉じていることを特徴とする請求項１０に記載の誘導加熱装置である。
本発明によれば、冷却ファンの風又は空気が赤外線センサの周囲を流れることを更に防止できる。本発明は、赤外線センサの雰囲気温度を更に一定にして、高い精度で被加熱調理容器の温度を検出する誘導加熱装置を実現できるという作用を有する。
【００２５】
請求項１４に記載の発明は、前記赤外線センサは、螺旋状に設けられた前記誘導加熱手段の中心部に配置され、前記誘導加熱手段と前記赤外線センサとの間にフェライトを設けることを特徴とする請求項１に記載の誘導加熱装置である。
フェライトを設けることにより、誘導加熱手段の発する磁束が赤外線センサに悪影響を与えることを防止できる。本発明は、高い精度で被加熱調理容器の温度を検出する誘導加熱装置を実現できるという作用を有する。
【００２６】
【実施例】
以下本発明の実施をするための最良の形態を具体的に示した実施例について、図面とともに記載する。
【００２７】
《実施例１》
図１、４及び６を用いて、本発明の実施例１の誘導加熱装置を説明する。図６は、本発明の実施例１の誘導加熱装置の概略的な構成を示す断面図である。図６は従来例において説明した。図１は、本発明の実施例１の誘導加熱装置の構成を示す要部断面図である。図４は、本発明の実施例１の制御ユニットの概略的な分解斜視図である。図１及び図４において、１は誘導加熱装置の外郭を構成する本体である。本体１の上面は、トッププレート２で構成される。トッププレート２は、調理容器を載置する載置部３を有する。トッププレート２の載置部３の下部に誘導加熱コイル（誘導加熱手段）４を有する。誘導加熱コイル４は、調理容器５３（被加熱調理容器。図示しない。）を誘導加熱する。
【００２８】
５は赤外線センサである。赤外線センサ５は、調理容器の底面から放射される赤外線をトッププレート２越しに検知して温度に応じた信号を出力する。赤外線センサ５は、トッププレート２の上面より下１５ミリ〜３５ミリの位置に配設される。好ましくは、２６ミリである。
【００２９】
６は、誘導加熱中に発生する誘導加熱コイル４からの磁束漏れを抑制する防磁部材である。実施例１において、防磁部材６はアルミのダイカスト製であって、筒体６ａの内面はローラーバリッシングによって鏡面仕上げされる。防磁部材６の肉厚は、１．５ミリ〜５ミリである。好ましくは肉厚は２ミリである。アルミは、赤外線センサ５の反射率が高く（調理容器５３が放射した赤外線を少ない損失で赤外線センサ５に伝え）、アルミ自体の赤外線放射が少ない（調理容器５３が放射した赤外線のＳ／Ｎ比（信号対ノイズ比）を劣化させにくい。）。防磁部材６は、筒体６ａを有する。筒体６ａが防磁部材６に一体化された構造とすることにより、赤外線センサ５と筒体６ａの位置精度が高まる。筒体６ａは、調理容器５３が放射した赤外線を少ない損失で赤外線センサ５に伝達し、誘導加熱コイル４からの磁束が赤外線センサ５に洩れることを防止する。防磁部材６が赤外線センサ５及び制御基板７を覆うことにより赤外線センサ５及び制御基板７周辺の雰囲気温度を安定化している。
【００３０】
７は制御基板である。制御基板７は誘導加熱コイル４の出力を制御する。具体的には、制御基板７上には温度算出手段５１及び制御手段５２が設けられている。温度算出手段５１は、赤外線センサ５の出力信号に基づいて調理容器５３の温度を算出する。制御手段５２は、温度算出手段５１から得た情報をもとに誘導加熱コイル４への電力供給を制御する。
８はシールドプレートである。シールドプレート８は、制御基板７の下方を略覆っている。シールドプレート８は、制御基板の下側から回り込む磁束を遮蔽し、その影響を防止する。防磁部材６及びシールドプレート８はビス１２ｂで接地される。
【００３１】
９は第１の樹脂カバーである。第１の樹脂カバー９は、防磁部材６及びシールドプレート８を保持する。第１の樹脂カバー９と防磁部材６とはビス１２ａ、１２ｂ、１２ｃで結合されて略閉空間を構成し、その中に赤外線センサ５、制御基板７、シールドプレート８を収納する（「制御ユニット」と呼ぶ。）。本発明の誘導加熱装置は本体の下部にファン（図示していない。）を有し、ファンは誘導加熱コイル４に冷却風を送ることで誘導加熱コイル４の発熱を抑えている。第１の樹脂カバー９と防磁部材６とで構成された略閉空間は、下方からの冷却風が赤外線センサ５の周りを流れることを防止する。これにより、赤外線センサ５の周りの雰囲気温度を安定させ、高い温度検出精度を実現している。
これに代えて、第１の樹脂カバー９の底面が下方に開口しており、シールドプレート８がその底面を塞いでも良い。この場合、第１の樹脂カバー９とシールドプレート８と防磁部材６とは略閉空間を構成し、その中に赤外線センサ５と制御基板７とを収納する。
【００３２】
制御基板７（回路基板）上に第２の樹脂カバー１３が設けられている。第２の樹脂カバー１３は、赤外線センサ５を制御基板７から所定の高さの位置に保持する。第２の樹脂カバー１３は、赤外線センサ５と赤外線センサ５が取り付けられている制御基板７との間に配置され、調理容器５３が放射する赤外線から制御基板７を略遮蔽する。赤外線センサ５の端子は制御基板７に直接半田付けされている。第２の樹脂カバー１３は、赤外線センサ５を載置する保持面１３ａを有し、防磁部材６が下方向に開口した凹部６ｂを有し、保持面１３ａが凹部６ｂの中に位置し、第２の樹脂カバー１３及び凹部６ｂで規定される空間の側面及び底面が略閉じている。これにより、冷却ファンの風又は空気が赤外線センサの周囲を流れることを更に防止できる。赤外線センサ５の雰囲気温度を更に一定にして、高い精度で調理容器５３の温度を検出できる。
【００３３】
１０、１１は、防磁効果を有するフェライトである。フェライト１０は、誘導加熱コイル４と赤外線センサ５との間であって、赤外線センサ５を通る垂直の軸を中心とする円上に設けられる。フェライト１０の上面は誘導加熱コイル４の上面より上にあり、フェライト１０の下面は誘導加熱コイル４の最外周と赤外線センサ５とを結ぶ線がフェライトによって遮蔽されるように下方に伸びている。フェライト１１は放射線状に形成される。
【００３４】
以上の構成により、赤外線センサ５は、加熱調理中に発生する誘導加熱コイル４からの誘導磁界の影響を受けにくくなる。漏洩磁束により赤外線センサ５自体が発熱することを抑えられるため、正確な温度検知ができ、安定した加熱制御を実現できる。
【００３５】
《実施例２》
図２及び図６を用いて、本発明の実施例２の誘導加熱装置を説明する。図６は、本発明の実施例２の誘導加熱装置の概略的な構成を示す断面図である。図２は、本発明の実施例２の誘導加熱装置の構成を示す要部断面図である。実施例２の誘導加熱装置は、防磁部材２１の筒体が実施例１と異なる。それ以外の構成は、実施例１と同一であるので同じ構成部品には同一符号を付し、その説明を省略する。
【００３６】
実施例２の防磁部材２１について説明する。防磁部材２１は、略同軸の二重の筒体２１ａ及び２１ｂを有する。筒体を二重の構成としたことにより、赤外線センサ５への防磁効果をさらに高めるとともに、熱容量の増大により赤外線センサ５及び制御基板７の周りの雰囲気温度を更に安定に維持する。実施例２の誘導加熱装置は、更に高い精度で温度検知を行うことができる。
筒体２１ａと２１ｂとを一体化して構成することにより、筒体２１ａと２１ｂとの間に均一な空隙（断熱効果を有する。）が確保できるため、赤外線センサ５周辺の雰囲気温度は格段に安定化できる。さらに、赤外線センサ５と防磁部材２１の位置精度が高まることで、より正確な温度検知ができ、安定した加熱制御ができる。
【００３７】
《実施例３》
図３及び図６を用いて、本発明の実施例３の誘導加熱装置を説明する。図６は、本発明の実施例３の誘導加熱装置の概略的な構成を示す断面図である。図３は、本発明の実施例３の誘導加熱装置の構成を示す要部断面図である。実施例３の誘導加熱装置は、防磁部材３１が開口部３２を有することが実施例２と異なる。それ以外の構成は、実施例２と同一であるので同じ構成部品には同一符号を付し、その説明を省略する。
【００３８】
実施例３の防磁部材３１について説明する。防磁部材３１は、略同軸の二重の筒体３１ａ及び３１ｂとの間に開口部３２を有する。実施例２において、開口部３２は４つである。筒体３１ｂが発熱した場合であっても、開口部３２で熱切りすることにより、筒体３１ａへの熱伝導を更に少なくし、赤外線センサ５周辺の雰囲気温度を安定化できる。
【００３９】
【発明の効果】
本発明によれば、赤外線センサが取り付けられ、その出力する検出信号に基づいて被加熱調理容器の温度を検知する制御基板を防磁部材で覆うことにより、誘導加熱手段からの漏洩磁束の影響を受けることなく、赤外線センサが安定した温度検知を行う誘導加熱装置を実現できるという有利な効果が得られる。
本発明は、防磁部材の筒体と側部とを一体で構成することにより、高い施工性を実現する。本発明によれば、高い寸法精度を有し、部品点数が少なく、優れた組立作業性を有する誘導加熱装置を実現できるという有利な効果が得られる。
【００４０】
本発明は、筒体を略同軸にして二重に形成した構成とすることにより、磁束が赤外線センサに洩れ込むことを防止する防磁効果をさらに高めるとともに防磁部材の熱容量の増大により赤外線センサの周りの雰囲気の温度を更に安定して維持する。本発明によれば、高い精度で温度検知を行う誘導加熱装置を実現できるという有利な効果が得られる。
【００４１】
二重の筒体の外側と内側のつなぎ部に開口部を設けた構成とすることにより、たとえ外側の筒体が加熱されたとしても、赤外線センサを搭載する中央までの熱抵抗が大きくなり赤外線センサの周りの雰囲気温度の急激な変化を回避できる。本発明によれば、更に安定した温度検知が行える誘導加熱装置を実現できるという有利な効果が得られる。
【図面の簡単な説明】
【図１】本発明の実施例１における誘導加熱装置の構成を示す要部断面図
【図２】本発明の実施例２における誘導加熱装置の構成を示す要部断面図
【図３】本発明の実施例３における誘導加熱装置の構成を示す要部断面図
【図４】本発明の実施例１〜３の制御ユニットの分解斜視図
【図５】感熱素子を用いた従来の誘導加熱装置の構成を示す断面図
【図６】赤外線センサを用いた誘導加熱装置の構成を示す断面図
【符号の説明】
１本体
２トッププレート
３載置部
４誘導加熱コイル
５赤外線センサ
６、２１、３１防磁部材
６ａ、２１ａ、２１ｂ、３１ａ、３１ｂ筒体
７制御基板
８シールドプレート
９第１の樹脂カバー
１０、１１フェライト
１２ａ、１２ｂ、１２ｃビス
１３第２の樹脂カバー
３２開口部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an induction heating apparatus provided with an infrared sensor.
[0002]
[Prior art]
In recent years, induction heating devices have spread to the market as cookers that do not use fire. A conventional induction heating apparatus will be described with reference to FIGS.
The induction heating apparatus of Conventional Example 1 will be described with reference to FIG. FIG. 5 is a cross-sectional view showing the configuration of the induction heating apparatus of Conventional Example 1 using a thermal element. The induction heating device of Conventional Example 1 includes a main body 1 that constitutes an outer shell, a top plate 2 that is formed of a non-magnetic material and on which a cooking vessel 53 is placed, and is disposed below the top plate 2 and induction heating the cooking vessel 53 An induction heating coil 4, a thermal element 54 that is pressed against the back surface of the top plate 2 and outputs a detection signal corresponding to the temperature, a temperature calculation means 51, and a control means 52. The induction heating device of Conventional Example 1 detects the temperature of the bottom surface of the cooking container 53 placed on the top plate 2 using a thermal element. The temperature calculation means 51 calculates the temperature of the cooking container 53 based on the output signal of the thermal element 54. The control means 52 controls the supply of electric power to the induction heating coil 4 based on the temperature information obtained from the temperature calculation means 51.
[0003]
A high frequency current is supplied to the induction heating coil 4 by the control means 52. The induction heating coil 4 generates a high frequency magnetic field. The high frequency magnetic field is linked to the cooking container 53, and the cooking container 53 itself is induction-heated to generate heat. The food stored in the cooking container 53 is heated by the heat generated by the cooking container 53, and cooking proceeds. The control means 52 controls the temperature of the food by adjusting the power supplied to the induction heating coil 4 based on the temperature signal detected by the temperature calculation means 51.
[0004]
The thermal element 54 detects the temperature of the cooking container 53 via the top plate 2. The top plate 2 is made of ceramic and has a low thermal conductivity. Therefore, a delay occurs in the temperature detection of the cooking container 53 by the heat sensitive element 54, and the conventional induction heating apparatus has a problem that it is inferior in thermal responsiveness.
[0005]
The induction heating apparatus of Conventional Example 2 will be described with reference to FIG. FIG. 6 is a cross-sectional view showing a configuration of an induction heating device of Conventional Example 2 using an infrared sensor. 6 is different from FIG. 5 in that the infrared sensor 5 is provided instead of the thermal element 54. The other constituent elements are the same as those in FIG.
The infrared sensor 5 is disposed below the top plate 2, detects infrared rays emitted from the bottom surface of the cooking container 53 through the top plate 2, and outputs a signal corresponding to the temperature. The temperature calculation means 51 calculates the temperature of the cooking container 53 based on the output signal of the infrared sensor 5. The control unit 52 controls power supply to the induction heating coil 4 based on the information obtained from the temperature calculation unit 51.
The infrared rays radiated from the cooking container 53 pass through the top plate 2 and reach the infrared sensor 5. In the temperature detection method using the infrared sensor 5, the problem of poor thermal response has been overcome (see, for example, Patent Document 1).
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 03-184295
[Problems to be solved by the invention]
However, when the infrared sensor 5 is disposed in the vicinity of the induction heating coil 4 as in the configuration of the induction heating device of the conventional example 2 using the infrared sensor, an induction magnetic field generated from the induction heating coil 4 during cooking is generated. As a result, the infrared sensor 5 itself generates heat. Therefore, the conventional induction heating apparatus has a problem that accurate temperature detection cannot be performed and stable heating control cannot be performed.
An object of the present invention is to provide an induction heating apparatus in which an infrared sensor performs stable temperature detection without being affected by leakage magnetic flux from induction heating means. Objective.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, an induction heating device of the present invention includes a main body constituting an outer shell, a top plate provided on an upper surface of the main body, and having at least one placement portion on which a cooked cooking container is placed; An induction heating means for heating the cooked cooking container, and an infrared ray radiated from the cooked cooking container, which is provided below the placement section and is heated in the vicinity of the induction heating means. an infrared sensor for outputting a detection signal corresponding, the infrared sensor is mounted, a control board you test knowledge the temperature of the heated cooking container based on the detected signal, and a cylindrical member covering the periphery of the infrared sensor , having a magnetic shielding member made of a piece having a side for covering the control board.
The present invention has an effect that an infrared heating sensor can stably realize temperature detection with high accuracy without being affected by leakage magnetic flux from the induction heating means.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 is a main body constituting the outer shell, a top plate provided on the upper surface of the main body and having at least one placement portion for placing the cooked cooking container, and below the placement portion. An induction heating means for heating the heated cooking container; and an infrared ray radiated from the heated cooking container that is provided in the vicinity of the induction heating means and outputs a detection signal corresponding to the amount of light. an infrared sensor for the infrared sensor is mounted, a control board you test knowledge the temperature of the heated cooking container based on the detected signal, and a cylindrical member covering the periphery of the infrared sensor, the control board It is an induction heating apparatus characterized by having the magnetic-shielding member comprised integrally with the side part to cover.
[0010]
According to the present invention, the infrared sensor is not easily affected by the induction magnetic field from the induction heating means generated during cooking. The present invention has the effect of realizing an induction heating device that suppresses heat generation of the infrared sensor itself due to the magnetic effect of the induction heating coil.
The present invention can stabilize the ambient temperature around the infrared sensor by using a non-magnetic cylindrical body, and thus has an effect of realizing an induction heating device capable of accurately detecting temperature and performing stable heating control.
The present invention includes an infrared sensor is mounted, by covering the control board for detecting the temperature of the heated cooking container based on the detection signal to the output at the side of the magnetic shielding member, the control board from the induction heating coil It has the effect | action that the induction heating apparatus which can perform the stable temperature detection by an infrared sensor without being influenced by the leakage magnetic flux can be realized.
This invention implement | achieves high workability | operativity by comprising integrally the cylindrical body and side part of a magnetic-shielding member. Thereby, the attachment position accuracy of an infrared sensor and a magnetic-shielding member can be improved. The present invention has an effect that an induction heating device having high dimensional accuracy, a small number of parts, and excellent assembly workability can be realized.
[0011]
The invention according to claim 2 is the induction heating apparatus according to claim 1, wherein the cylindrical body is formed into a double cylindrical body substantially coaxially.
According to the present invention, the magnetic shielding effect for preventing magnetic flux from leaking into the infrared sensor can be further enhanced, and the temperature of the atmosphere around the infrared sensor can be more stably maintained by increasing the heat capacity of the magnetic shielding member. The present invention has an effect that an induction heating device that performs temperature detection with high accuracy can be realized.
[0012]
Invention of Claim 3 has an opening part in the connection part of the said cylinder body inside and the said cylinder body outside, It is an induction heating apparatus of Claim 2 characterized by the above-mentioned.
In the present invention, even when the outer cylinder is heated, heat conduction to the inner cylinder is reduced by heat cutting at the opening, and a significant increase in the ambient temperature around the infrared sensor is prevented. The present invention has the effect of realizing an induction heating device capable of stable temperature detection.
[0013]
A fourth aspect of the present invention is the induction heating apparatus according to the first aspect, wherein the magnetic shield member is made of aluminum. Aluminum has a high reflectance of the infrared sensor (transmits the infrared radiation emitted from the cooked cooking container to the infrared sensor with a small loss), and the infrared radiation of the aluminum itself is small (the S / N ratio of the infrared radiation emitted from the cooked cooking container (It is difficult to degrade the signal-to-noise ratio). The present invention has an effect that an induction heating device that performs temperature detection with high accuracy can be realized.
[0014]
The invention according to claim 5 is the induction heating apparatus according to claim 1, wherein the magnetic-shielding member is made of die-cast, and the inner surface of the cylindrical body is formed by mirror finishing. The present invention has an effect that an induction heating device capable of accurately detecting infrared rays can be realized. Thereby, the magnetic-shielding member of a complicated shape can be formed with high precision. In order to obtain a sufficient magnetic-shielding effect, it is preferable that the magnetic-shielding member is thick to some extent. The magnetic shielding member can be formed with an optimum thickness by die casting. By mirror-finishing the inner surface of the die-cast cylinder, the infrared radiation emitted from the cooked container can be transmitted to the infrared sensor with little loss.
When the cylinder is double, the inner surface of the inner cylinder may be mirror-finished.
[0016]
In a sixth aspect of the present invention, the distance between the upper surface of the top plate and the upper surface of the infrared sensor is in the range of 15 mm to 35 mm. It is.
When the distance from the top plate of the infrared sensor is short, the infrared sensor becomes too hot due to the influence of leakage magnetic flux from the induction heating means. When the distance from the top plate is far, the input of infrared rays emitted from the cooking container to be heated becomes small. Therefore, the distance between the upper surface of the top plate and the upper surface of the infrared sensor is set in the range of 15 mm to 35 mm. In this range, the infrared sensor is not easily affected by the leakage magnetic flux from the induction heating means, and can receive a sufficient amount of infrared rays. Preferably, the optimum value of the distance between the top surface of the top plate and the top surface of the infrared sensor is 26 mm.
[0017]
The invention according to claim 7, the thickness of the magnetic shielding member is an inductive heating apparatus according to claim 1, characterized in that in the range of 1.5 millimeters to 5 millimeters. If the thickness of the magnetic-shielding member is thin, the magnetic-shielding effect is thinned. If the thickness of the magnetic-shielding member is thick, a nest enters the interior after molding and the magnetic-shielding effect is reduced. Therefore, the magnetic-shielding member is formed almost uniformly in the range of 1.5 mm to 5 mm. Preferably, the standard thickness of the magnetic-shielding member is 2 mm.
[0018]
The invention according to claim 8 is the induction heating apparatus according to claim 1, further comprising a shield plate that substantially covers a lower portion of the control board.
As a result, the magnetic flux that wraps around from the lower side of the control board can be shielded and its influence can be prevented. The present invention further has the effect of realizing an induction heating device that is less susceptible to leakage magnetic flux.
[0019]
The invention according to claim 9 is the induction heating device according to claim 1 or 8 , wherein the magnetic shield member, or the magnetic shield member and the shield plate are grounded. The present invention further has the effect of realizing an induction heating device that is less susceptible to leakage magnetic flux.
[0020]
Invention according to claim 1 0, wherein the magnetically shielded member, or the magnetism prevention first further comprising a resin cover which holds the member and the shield plate, wherein the first resin cover, the magnetically shielded member or the magnetic-shield member The induction heating apparatus according to claim 1 or 8 , wherein the shield plate forms a substantially closed space, and the infrared sensor and the control board are housed therein.
[0021]
The induction heating apparatus typically has a fan at the lower part of the main body, and the fan suppresses heat generation of the induction heating means by sending cooling air to the induction heating means. However, when this wind passes around the infrared sensor, the ambient temperature around the infrared sensor becomes unstable, and the temperature detection accuracy of the heated cooking container by the infrared sensor deteriorates. In the present invention, a substantially closed space is constituted by a resin cover and a magnetic shield member, and an infrared sensor and a control board are housed therein, thereby preventing cooling air from passing through the substantially closed space. The present invention has an effect of realizing an induction heating device that detects the temperature of the cooking container to be heated with high accuracy while keeping the ambient temperature of the infrared sensor and the control board constant.
[0022]
The invention of claim 1 1, wherein the infrared sensor and the disposed between the circuit board infrared sensor is mounted, the second of the heated cooking container is substantially shields the circuit board from the infrared emitting The induction heating apparatus according to claim 1, further comprising a resin cover. Thereby, it can prevent that the infrared rays radiated | emitted from the to-be-heated cooking container deteriorate a circuit board with time.
[0023]
The invention according to claim 1 2, wherein the second resin cover, the induction heating according to the infrared sensor, to claim 1 1, wherein the holding from the circuit board to the position of a predetermined height Device. The second resin cover stably holds the infrared sensor at a predetermined height from the circuit board, so that the infrared sensor can be disposed above the bottom surface of the magnetic member cylinder. Thereby, the infrared rays emitted from the cooking container to be heated can be transmitted to the infrared sensor with even less loss.
[0024]
The invention according to claim 1 3, further comprising a second resin cover having a holding surface for mounting the infrared sensor has a recess in which the magnetic shield member is opened downward, the holding surface is the located in the recess, an induction heating apparatus according to claim 1 0, characterized in that side and bottom surfaces of the second resin cover and the space defined by the recessed portion is substantially closed.
According to the present invention, it is possible to further prevent the wind or air of the cooling fan from flowing around the infrared sensor. The present invention has an effect that it is possible to realize an induction heating apparatus that detects the temperature of the cooking container to be heated with high accuracy by further maintaining the atmospheric temperature of the infrared sensor.
[0025]
The invention according to claim 1 4, wherein the infrared sensor, characterized in that arranged in the center of the induction heating means provided in a spiral shape, providing a ferrite between said induction heating means and the infrared sensor The induction heating apparatus according to claim 1.
By providing the ferrite, the magnetic flux generated by the induction heating means can be prevented from adversely affecting the infrared sensor. The present invention has an effect that an induction heating device that detects the temperature of a cooking container to be heated can be realized with high accuracy.
[0026]
【Example】
Hereinafter, examples specifically showing the best mode for carrying out the present invention will be described with reference to the drawings.
[0027]
Example 1
The induction heating apparatus according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a cross-sectional view illustrating a schematic configuration of the induction heating apparatus according to the first embodiment of the present invention. FIG. 6 is described in the conventional example. FIG. 1 is a cross-sectional view of a principal part showing the configuration of the induction heating apparatus of Example 1 of the present invention. FIG. 4 is a schematic exploded perspective view of the control unit according to the first embodiment of the present invention. In FIGS. 1 and 4, reference numeral 1 denotes a main body that constitutes the outline of the induction heating apparatus. The upper surface of the main body 1 is composed of a top plate 2. The top plate 2 has a placement portion 3 on which the cooking container is placed. An induction heating coil (induction heating means) 4 is provided below the mounting portion 3 of the top plate 2. The induction heating coil 4 induction-heats the cooking container 53 (heated cooking container, not shown).
[0028]
Reference numeral 5 denotes an infrared sensor. The infrared sensor 5 detects infrared rays emitted from the bottom surface of the cooking container through the top plate 2 and outputs a signal corresponding to the temperature. The infrared sensor 5 is disposed at a position 15 mm to 35 mm below the upper surface of the top plate 2. Preferably, it is 26 mm.
[0029]
6 is a magnetic-shielding member that suppresses magnetic flux leakage from the induction heating coil 4 that occurs during induction heating. In Example 1, the magnetic-shielding member 6 is made of aluminum die-casting, and the inner surface of the cylindrical body 6a is mirror-finished by roller burring. The thickness of the magnetic shielding member 6 is 1.5 mm to 5 mm. Preferably the wall thickness is 2 mm. Aluminum has a high reflectance of the infrared sensor 5 (transmits infrared rays emitted from the cooking container 53 to the infrared sensor 5 with a small loss), and aluminum emits little infrared radiation (S / N ratio of infrared rays emitted from the cooking container 53) (It is difficult to degrade the signal-to-noise ratio). The magnetic shielding member 6 has a cylindrical body 6a. By adopting a structure in which the cylindrical body 6a is integrated with the magnetic shielding member 6, the positional accuracy of the infrared sensor 5 and the cylindrical body 6a is increased. The cylindrical body 6a transmits the infrared rays radiated from the cooking container 53 to the infrared sensor 5 with little loss, and prevents the magnetic flux from the induction heating coil 4 from leaking to the infrared sensor 5. The magnetic shielding member 6 covers the infrared sensor 5 and the control board 7 to stabilize the ambient temperature around the infrared sensor 5 and the control board 7.
[0030]
Reference numeral 7 denotes a control board. The control board 7 controls the output of the induction heating coil 4. Specifically, a temperature calculation unit 51 and a control unit 52 are provided on the control board 7. The temperature calculation means 51 calculates the temperature of the cooking container 53 based on the output signal of the infrared sensor 5. The control unit 52 controls power supply to the induction heating coil 4 based on the information obtained from the temperature calculation unit 51.
Reference numeral 8 denotes a shield plate. The shield plate 8 substantially covers the lower part of the control board 7. The shield plate 8 shields the magnetic flux that flows from the lower side of the control board and prevents its influence. The magnetic shielding member 6 and the shield plate 8 are grounded with screws 12b.
[0031]
Reference numeral 9 denotes a first resin cover. The first resin cover 9 holds the magnetic shielding member 6 and the shield plate 8. The first resin cover 9 and the magnetic shielding member 6 are coupled by screws 12a, 12b, and 12c to form a substantially closed space, and the infrared sensor 5, the control board 7, and the shield plate 8 are accommodated therein ("control unit""). The induction heating device of the present invention has a fan (not shown) at the lower part of the main body, and the fan suppresses heat generation of the induction heating coil 4 by sending cooling air to the induction heating coil 4. The substantially closed space formed by the first resin cover 9 and the magnetic shielding member 6 prevents cooling air from below from flowing around the infrared sensor 5. Thereby, the ambient temperature around the infrared sensor 5 is stabilized and high temperature detection accuracy is realized.
Instead, the bottom surface of the first resin cover 9 may be opened downward, and the shield plate 8 may block the bottom surface. In this case, the first resin cover 9, the shield plate 8, and the magnetic-shielding member 6 constitute a substantially closed space, and the infrared sensor 5 and the control board 7 are accommodated therein.
[0032]
A second resin cover 13 is provided on the control board 7 (circuit board). The second resin cover 13 holds the infrared sensor 5 at a predetermined height from the control board 7. The second resin cover 13 is disposed between the infrared sensor 5 and the control board 7 to which the infrared sensor 5 is attached, and substantially shields the control board 7 from infrared rays emitted from the cooking container 53. The terminals of the infrared sensor 5 are directly soldered to the control board 7. The second resin cover 13 has a holding surface 13a on which the infrared sensor 5 is placed, the magnetic-shielding member 6 has a recess 6b that opens downward, the holding surface 13a is located in the recess 6b, The side surface and the bottom surface of the space defined by the resin cover 13 and the recess 6b are substantially closed. Thereby, it is possible to further prevent the wind or air of the cooling fan from flowing around the infrared sensor. It is possible to detect the temperature of the cooking container 53 with high accuracy by making the atmospheric temperature of the infrared sensor 5 more constant.
[0033]
Reference numerals 10 and 11 are ferrites having a magnetic shielding effect. The ferrite 10 is provided between the induction heating coil 4 and the infrared sensor 5 on a circle centered on a vertical axis passing through the infrared sensor 5. The upper surface of the ferrite 10 is above the upper surface of the induction heating coil 4, and the lower surface of the ferrite 10 extends downward so that a line connecting the outermost periphery of the induction heating coil 4 and the infrared sensor 5 is shielded by the ferrite. The ferrite 11 is formed in a radial shape.
[0034]
With the above configuration, the infrared sensor 5 is not easily affected by the induction magnetic field from the induction heating coil 4 generated during cooking. Since the infrared sensor 5 itself can be prevented from generating heat due to the leakage magnetic flux, accurate temperature detection can be performed, and stable heating control can be realized.
[0035]
Example 2
An induction heating apparatus according to Embodiment 2 of the present invention will be described with reference to FIGS. FIG. 6 is a cross-sectional view illustrating a schematic configuration of the induction heating apparatus according to the second embodiment of the present invention. FIG. 2 is a cross-sectional view of the main part showing the configuration of the induction heating apparatus of Example 2 of the present invention. The induction heating device of the second embodiment is different from the first embodiment in the cylindrical body of the magnetic shielding member 21. Since other configurations are the same as those of the first embodiment, the same components are denoted by the same reference numerals, and description thereof is omitted.
[0036]
The magnetic-shielding member 21 of Example 2 is demonstrated. The magnetic-shield member 21 includes substantially coaxial double cylinders 21a and 21b. Since the cylindrical body has a double structure, the magnetic shielding effect on the infrared sensor 5 is further enhanced, and the ambient temperature around the infrared sensor 5 and the control board 7 is further stably maintained by increasing the heat capacity. The induction heating apparatus according to the second embodiment can perform temperature detection with higher accuracy.
By integrating the cylinders 21a and 21b, a uniform gap (having a heat insulating effect) can be secured between the cylinders 21a and 21b, so the ambient temperature around the infrared sensor 5 is remarkably stable. Can be Furthermore, since the positional accuracy of the infrared sensor 5 and the magnetic-shielding member 21 increases, more accurate temperature detection can be performed and stable heating control can be performed.
[0037]
Example 3
An induction heating apparatus according to Embodiment 3 of the present invention will be described with reference to FIGS. 3 and 6. FIG. 6 is a cross-sectional view illustrating a schematic configuration of the induction heating apparatus according to the third embodiment of the present invention. FIG. 3 is a cross-sectional view of the main part showing the configuration of the induction heating apparatus of Example 3 of the present invention. The induction heating apparatus according to the third embodiment is different from the second embodiment in that the magnetic shield member 31 has an opening 32. Since other configurations are the same as those of the second embodiment, the same components are denoted by the same reference numerals, and description thereof is omitted.
[0038]
The magnetic-shielding member 31 of Example 3 is demonstrated. The magnetic-shield member 31 has an opening 32 between the substantially coaxial double cylinders 31a and 31b. In the second embodiment, there are four openings 32. Even when the cylindrical body 31b generates heat, heat conduction to the cylindrical body 31a can be further reduced by cutting the heat through the opening 32, and the ambient temperature around the infrared sensor 5 can be stabilized.
[0039]
【The invention's effect】
According to the present invention, an infrared sensor is mounted, by covering the control board for detecting the temperature of the heated cooking container based on the detection signal output by the magnetic-shield member, the effects of leakage flux from the induction heating means There is an advantageous effect that an induction heating device can be realized in which the infrared sensor performs stable temperature detection without receiving the heat.
This invention implement | achieves high workability | operativity by comprising integrally the cylindrical body and side part of a magnetic-shielding member. According to the present invention, it is possible to obtain an advantageous effect that an induction heating device having high dimensional accuracy, a small number of parts, and excellent assembly workability can be realized.
[0040]
The present invention has a structure in which the cylindrical body is substantially coaxially formed so as to be doubled, thereby further improving the magnetic shielding effect for preventing magnetic flux from leaking into the infrared sensor and increasing the heat capacity of the magnetic shielding member. The temperature of the atmosphere is maintained more stably. According to the present invention, an advantageous effect that an induction heating device that performs temperature detection with high accuracy can be realized.
[0041]
By adopting a structure in which an opening is provided in the joint between the outside and inside of the double cylinder, even if the outside cylinder is heated, the thermal resistance up to the center where the infrared sensor is mounted increases and the infrared A sudden change in the ambient temperature around the sensor can be avoided. According to the present invention, it is possible to obtain an advantageous effect that an induction heating apparatus that can perform more stable temperature detection can be realized.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part showing a configuration of an induction heating apparatus in Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of a main part showing a configuration of an induction heating apparatus in Embodiment 2 of the present invention. FIG. 4 is an exploded perspective view of the control unit of Examples 1 to 3 according to the present invention. FIG. 5 is a diagram of a conventional induction heating apparatus using a thermal element. Cross-sectional view showing the configuration [FIG. 6] Cross-sectional view showing the configuration of the induction heating device using the infrared sensor [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main body 2 Top plate 3 Mounting part 4 Induction heating coil 5 Infrared sensor 6, 21, 31 Magnetic-shield member 6a, 21a, 21b, 31a, 31b Cylindrical body 7 Control board 8 Shield plate 9 1st resin cover 10, 11 Ferrite 12a, 12b, 12c Screw 13 Second resin cover 32 Opening

Claims

A main body constituting the outer shell,
A top plate provided on the upper surface of the main body and having at least one placement portion for placing the cooked cooking container;
Inductive heating means provided below the placing portion for heating the cooking container to be heated,
An infrared sensor provided in the vicinity of the induction heating means, receiving infrared radiation emitted from the heated cooking container, and outputting a detection signal according to the amount of light;
The infrared sensor is mounted, a control board you test knowledge the temperature of the heated cooking container based on the detected signal,
A cylindrical body covering the periphery of the infrared sensor, and a side for covering the control board, and a magnetic-shield member configured integrally with,
An induction heating apparatus comprising:

The induction heating apparatus according to claim 1, wherein the cylindrical body is substantially coaxial and formed into a double cylindrical body.

The induction heating apparatus according to claim 2, wherein an opening is provided at a connecting portion between the inner cylinder and the outer cylinder.

The induction heating apparatus according to claim 1, wherein a material of the magnetic shielding member is aluminum.

The induction heating apparatus according to claim 1, wherein the magnetic shield member is made of die-casting, and an inner surface of the cylindrical body is formed by mirror finishing.

The induction heating apparatus according to claim 1, wherein a distance between an upper surface of the top plate and an upper surface of the infrared sensor is in a range of 15 mm to 35 mm.

The induction heating apparatus according to claim 1, wherein the thickness of the magnetic shielding member is in a range of 1.5 mm to 5 mm.

The induction heating apparatus according to claim 1, further comprising a shield plate that substantially covers a lower portion of the control board.

The induction heating apparatus according to claim 1 or 8 , wherein the magnetic shield member, or the magnetic shield member and the shield plate are grounded.

A first resin cover for holding the magnetic shield member, or the magnetic shield member and the shield plate;
2. The first resin cover, the magnetic shield member, or the magnetic shield member and the shield plate form a substantially closed space, and the infrared sensor and the control board are housed in the closed space. Or the induction heating apparatus of Claim 8 .

And a second resin cover which is disposed between the infrared sensor and the circuit board to which the infrared sensor is attached, and which substantially shields the circuit board from infrared rays radiated from the heated cooking container. The induction heating device according to claim 1.

The second resin cover, the induction heating apparatus according to the infrared sensor, to claim 1 1, wherein the holding from the circuit board to the position of a predetermined height.

A second resin cover having a holding surface on which the infrared sensor is placed; and the magnetic-shielding member has a recess opening downward, the holding surface being located in the recess, induction heating apparatus according to claim 1 0, characterized in that side and bottom surfaces of the space defined by the resin cover and the recess is substantially closed.

2. The induction heating according to claim 1, wherein the infrared sensor is disposed at a central portion of the induction heating unit provided in a spiral shape, and ferrite is provided between the induction heating unit and the infrared sensor. apparatus.